%% Author: kevin.jingqiu
%% Created: May 29, 2009
%% Description:
%% Find the greatest product of five consecutive digits in the 1000-digit number.
-module(p8).

%%
%% Include files
%%

%%
%% Exported Functions
%%
-export([solve/0, multi_five/1]).

%%
%% API Functions
%%
solve() -> p8("7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450", 1).

%%
%% Local Functions
%%
p8(List, Max) when length(List) < 5 -> Max;
p8([H|Rest], Max) ->
	[A, B, C, D | _] = Rest,
	io:format("H=~p, A=~p, B=~p, C=~p, D=~p ~n", [H, A, B, C, D]),
	Current = multi_five([H, A, B, C, D]),
	case Current > Max of
		true ->
			p8(Rest, Current);
		false ->
			p8(Rest, Max)
	end.

%% Take the first five element of the list
%% convert each of them into integers
%% and multiply them all
multi_five([A, B, C, D, E|_]) ->
	mylib:multi_all(lists:map(fun(X)->list_to_integer([X]) end, [A, B, C, D, E])).


